Suppose that, for every event, whether mental or physical, there is some physical event causally sufficient for it. Suppose, moreover, that physical reductionism in its various forms fails—that mental properties cannot be reduced to physical properties and mental events cannot be reduced to physical events. In this case, how could there be mental causation? More specifically, how could mental events cause other mental events, physical events, and intentional actions? The primary goal of this paper is to answer this question.